Conventionally, there has been known an illumination system where a plurality of illumination apparatuses are placed on a ceiling surface and a floor surface that is opposed to the ceiling surface is irradiated with light. In this illumination system, a sensor detects presence of a person who is located in a space where illumination apparatuses are placed (hereinafter, illumination space), and only a necessary illumination apparatus is turned on, thereby reducing power consumption.
According to Patent Literature 1 for example, there has proposed an illumination system that includes a plurality of illumination apparatuses placed on a ceiling surface, a camera that captures the entire illumination space, a calculation unit that calculates a position of a person based on an image of the camera, and a control unit that controls the illumination apparatuses in accordance with the position of the person. According to this illumination system, the control unit stores beforehand therein irradiation range information indicating an irradiation range of each of the illumination apparatuses, specifies an illumination apparatus whose irradiation range includes the position of the person calculated by the calculation unit among the illumination apparatuses. Then, the control unit turns on the specified illumination apparatus while keeping the illumination apparatuses other than the specified illumination apparatus in OFF state. In such an illumination system, only a minimum necessary illumination apparatus is turned on, thereby reducing power consumption in the entire illumination system.
Compared with this, in an illumination system for use in an office and the like where a person stays for a long time, there is a demand for giving comfort to a person who is located in an illumination space, in addition to reduction in power consumption. Especially, there is a demand for realizing brightness of the illumination space such that the person who is located in the illumination space feels comfortable.